j9国际集团

汇报标题 (Title)：Space-time structure and particle-fluid duality of solutions for the Boltzmann equation with hard potentials

（硬势Boltzmann方程解的时空结构与粒子-流体对偶）

汇报人 (Speaker)： 王海涛 教授（上海交通大学）

汇报功夫 (Time)：2025年11月13日（周四）15:00

汇报地址 (Place)：校本部GJ303

约请人(Inviter)：王宇澄

主办部门：理学院数学系

汇报提要：We study the quantitative pointwise behavior of solutions to the Boltzmann equation for hard potentials and Maxwellian molecules. A key challenge in this problem is the loss of velocity weight in linear estimates, which makes standard nonlinear iteration infeasible. To address this, we develop an Enhanced Mixture Lemma, demonstrating that mixing the transport and gain parts of the linearized collision operator can generate arbitrary-order regularity and decay in both space and velocity variables. This allows us to decompose the linearized solution into fluid (with arbitrary regularity and velocity decay) and particle (with rapid space-time decay but loss of velocity decay) components, making it possible to solve the nonlinear problem through this particle–fluid duality.